Description of problem:
When running the newest kernel (3.19.1-201.fc21.x86_64) on Toshiba Z30-B laptop the screen brightness is always very high and cannot be changed.
FN+F6 does not work, but it cannot be change using the brightness control in Gnome or in XFCE either.
The problem remains on the kernel from the Fedora Update Testing repository (3.19.2-200.fc21.x86_64)
It works on previous kernels, e.g. 3.17.4-301.fc21 3.18.9-200.fc21.x86_64
Version-Release number of selected component (if applicable):
Fedora 21, kernel 3.19.1-201.fc21.x86_64 and 3.19.2-200.fc21.x86_64
Boot using the most recent kernel, and it does not work. Neither on GNOME nor on XFCE.
Boot using an older kernel, and it works.
Toshiba Z30-B-119 laptop. Intel i5-5200U CPU. FHD screen.
Fedora 21 64 bit.
Can you please try booting one of the new non working kernels with "video.use_native_backlight=0" added to the kernel commandline, and let us know if that fixes things.
Also please do:
sudo dmidecode > dmi.log
And attach the generated dmi.log file here please.
Thanks & Regards,
I added "video.use_native_backlight=0" to the kernel command line and the result is a little surprising:
the brightness control still does not work under the newest kernel (3.19.2-200.fc21.x86_64), but
it also stop working under the previous kernel (3.18.9-200.fc21.x86_64)
I also changed the value to 1 just to test what happens, and under the old kernel the brightness starts working normally but under the new kernel it still does not work.
I am attaching the dmi.log
Created attachment 1006865 [details]
Thanks for the testing and logs, can you please try using a newer kernel, e.g. :
Download the following rpms:
For your arch from there, save them all to the same directory (which should not contain other rpms) and do:
sudo rpm -ivh kernel-*.rpm
From within that directory.
Then reboot into the new kernel and see if that fixes things.
If that does not help can you please do:
And copy and paste the output from that command to this bug from 3 different boots:
1) An old working kernel
2) A new non working kernel without any special cmdline options
3) A new non working kernel with "video.use_native_backlight=0" on the kernel command line
(In reply to Hans de Goede from comment #4)
The newest kernel did not help (4.0.0-0.rc5.git3.1.fc22.x86_64), but I see the solution is close, thanks to your help.
The command ls /sys/class/backlight
gives the following output
1/ for an old working kernel
2/ for a new non working kernel (last release and git)
3/ for a new non working kernel with "video.use_native_backlight=0"
Waiting for the solution to be implemented in the kernel I figured I can do this:
echo 250 > /sys/class/backlight/intel_backlight/brightness
and adjust the brightness using the right number (e.g. 200, 250, 300, 400).
It is not very convenient but it works.
I wonder if this can be implemented in the kernel so that the keyboard shortcut uses it.
Ok, I think that this is caused by this upstream commit:
I've just started a scratch build of the fedora 3.19.3 kernel with that commit reverted:
Please download the following rpms:
For your arch from there (note this is still building atm).
Save them all to the same directory (which should not contain other rpms) and do:
sudo rpm -ivh kernel-*.rpm
From within that directory.
Then boot into the new kernel (without any special kernel commandline options) and check if the backlight works as expected.
Also please provide the output of:
ls -l /sys/class/backlight
On a *broken* kernel, so that we will know which version of the toshiba acpi interface your laptop has, as reverting the commit will cause a known issue on another model, so we need to figure out a way to make both models work.
Thanks & Regards,
With this new kernel the backlight works!
Here is the output of ls -l /sys/class/backlight on the broken kernel:
lrwxrwxrwx 1 root root 0 Apr 10 2015 intel_backlight -> ../../devices/pci0000:0
lrwxrwxrwx 1 root root 0 Apr 10 14:15 toshiba -> ../../devices/LNXSYSTM:00/LNXSY
Thanks for testing, and for the requested info. So now we know the culprit we need to come up with a way to fix this which does not break other Toshiba models. I'm currently discussing this with the upstream toshiba driver maintainer, see: https://bugzilla.kernel.org/show_bug.cgi?id=86521
In the mean time it is probably best if you keep using the scratch build.
After discussing this with upstream we've come up with a different fix, see:
https://bugzilla.kernel.org/show_bug.cgi?id=86521 for details.
I've started a new scratch-build with this fix, can you please test this once it is done building ? :
The test instructions are the same as before, note the kernel version now ends with rhbz1206036_2
the _2 is there so that you can distuingish this from the previous scratch build.
Thanks & Regards,
It works well!
(I tested 3.19.3-200.rhbz1206036_2.fc21.x86_64)
(In reply to Janusz from comment #12)
> It works well!
> (I tested 3.19.3-200.rhbz1206036_2.fc21.x86_64)
> Thank you
Thanks I've submitted the patch upstream, once it is accepted upstream I'll look into adding it to the official Fedora kernel builds, in the mean time it is probably best to keep using the second scratch build I've done.
Thank you. I appreciate your effort.
Unfortunately I discovered a strange bug in the second scratch build (3.19.3-200.rhbz1206036_2.fc21.x86_64)
It does not happen under the previous kernels. The previous scratch build works correctly as well.
(I've tested 3.18.9-200.fc21.x86_64 and 3.19.3-200.rhbz1206036.fc21.x86_64).
The problem description:
When I connect an external display before opening a session (when the login screen is displayed) the laptop freezes and the only solution is to keep the power button pressed until the PC is powered off. (Strangely enough I can see the login screen and the mouse pointer but everything else is frozen, even ctrl+alt+F2 does not work.)
When the external display is switched on during the session, it works, but the computer freezes when I log out.
This affects both HDMI and VGA outputs.
I am sorry I have not seen it before, but I was travelling and have not used any external display.
Do you still have the kernel from the first scratchbuild installed ? If so can you give that one a try and see if you can reproduce it there too? This sounds like an issue which is not related to the backlight fix, but likely something else which has broken in the newer kernels.
You are right, the first scratch build has the same issue. I just haven't noticed it.
I just tested 4.0.0.* kernel and it has the same bug.
I guess I should report it as a separate bug, right?
(In reply to Janusz from comment #17)
> You are right, the first scratch build has the same issue. I just haven't
> noticed it.
> I just tested 4.0.0.* kernel and it has the same bug.
> I guess I should report it as a separate bug, right?
*********** MASS BUG UPDATE **************
We apologize for the inconvenience. There is a large number of bugs to go through and several of them have gone stale. Due to this, we are doing a mass bug update across all of the Fedora 21 kernel bugs.
Fedora 21 has now been rebased to 3.19.5-200.fc21. Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.
If you have moved on to Fedora 22, and are still experiencing this issue, please change the version to Fedora 22.
If you experience different issues, please open a new bug report for those.
This is fixed by this upstream commit:
The patch has been added and will be in the 3.19.6 builds on F20/F21. F22 will get a build soon.
Thank you! I appreciate it.
kernel-3.19.6-200.fc21 has been submitted as an update for Fedora 21.
kernel-3.19.6-100.fc20 has been submitted as an update for Fedora 20.
* should fix your issue,
* was pushed to the Fedora 20 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing kernel-3.19.6-100.fc20'
as soon as you are able to, then reboot.
Please go to the following url:
then log in and leave karma (feedback).
The issue was fixed. (tested using 3.19.6-200.fc21.x86_64)
kernel-4.0.2-300.fc22 has been submitted as an update for Fedora 22.
kernel-3.19.7-100.fc20 has been submitted as an update for Fedora 20.
kernel-3.19.7-200.fc21 has been submitted as an update for Fedora 21.
kernel-4.0.2-300.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
kernel-3.19.7-200.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.
kernel-3.19.8-100.fc20 has been submitted as an update for Fedora 20.
kernel-3.19.8-100.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.